Process for the production of petroleum phenols



Nov. 10, 1942. R GERUCHER 2,301270 PROCESS FOR THE PRODUCTION OFPETROLEUM PHENOLS Filed Nov. 9, 1940 Sal EMT Sou 6N7 msarm/c; ZONE FEEDI 4 0/!- INLET PETROLEUM As /mu (mesa/v DIOXIDE I 5 Skew/one)PEENEEITION ZONE Saw/vanes 50Ll E/VT Team/v ZONE Ge Pl/E/VOLS WMWJ M vPatented Nov. 10, 1942 PRQQESS FOR THE PRODUCTION OF PETROLEUM PHENOLSRobert A. Gerlicher, Cranford, N. J., assigncr to Standard OilDevelopment Company, a corporation of Delaware Application November 9,1940, Serial No. 365,119

7 Claims.

The present invention is. concerned with an improved process for thesegregation and recovery of high quality naturally occurring acidicoxygen-containing compounds from oils containing the same. The inventionis more particularly concerned with the recovery of naturally occurringhigh molecular weight petroleum phenols from petroleum oils containingthe same. In accordance with the present process a petroleum oilfraction comprising naturally occurring high molecular weight phenols issegregated from a feed oil in an initial stage and then distilled in asecondary stage in the presence of a high molecular weight petroleumhydrocarbon such as a petroleum asphalt.

It is known in the art that valuable acidic oxygen-containing compoundssuch as naphthenic and phenolic type compounds are present in'mineraloils, particularly in petroleum oils boiling in the lubricating oil,kerosene, heavy naphtha, and heating oil boiling ranges especially inthose oil fractions derived from aromatic and naphthenic type crudes.These acidic oxygen-containing compounds are usually high molecularWeight phenolic constituents having a rather complex structure which areusually recovered from cracked petroleum naphtha distillates, heatingoil stocks, and other feed oils containing the same, by extractionoperations utilizing various solvents. In general, the feed petroleumoil fraction containing these constituents, as for example a heating oilfraction, is

treated with a strong aqueous or alcoholic caustic solution in order toform alkali metal phenolate salts.

handled in a manner to recover and purify the segregated phenols. Thisis usually accomplished by treating the aqueous alkaline solution with asolvent such as a petroleum ether or naphtha to remove the residualhydrocarbon constituents.

The solution of the salts is then usually treated with carbon dioxide orwith a weak mineral acid in a sufficient quantity to liberate thecorresponding phenols which are removed as a crude phenol fraction. Thiscrude phenol fraction contains various impurities and possesses adistinctive petroleum odor which in many cases prohibits their use. Thisis particularly true when it is desired to use the phenols for certaintypes of resins, since it is essential that the phenols which are to beutilized for this purpose contain less than 1% of oil and possess noobjectionable petroleum odor. It therefore has been the practice tocarefully distill the crude phenol product under vacuum conditionsadapted to remove a distilled phenolic product overhead and to remove asa bottoms a hard pitch-like substance which comprised the undesirable.impurities and decomposed phenols. This method The alkali metalphenolate salts in the alkaline solution are separated from the oil andI by means of line to.

of purification of the relatively high molecular weight phenols isundesirable in that the relatively high molecular weight phenolic typecompounds are decomposed, resulting in an appreciable loss in yields ofthese desirable constituents. Furthermore, the decomposition of some ofthe phenols materially increases the difficulties of producing arelatively pure phenolic distillate product.

I have now discovered a process by which crude phenols secured in themanner described may be readily and efiiciently handled to produce apure, high-quality product without any appreciable loss in yields of thedesired phenols occurring. In accordance with my invention the crudephenols are distilled in the presence of a relatively highboiling, highmolecular weight petroleum oil product, as for example a heavy asphalt.By operating in this manner a maximum overhead product is secured and acontinuous distillation operation may be carried out since the bottomsremain in the fluid state and may readily be removed from the still. Theprocess of my invention may be readily understood by reference to theattached drawing illustrating modifications of the same.

For purposes of illustration it is assumed that the phenol containingfeed oil is a segregated petroleum oil fraction boiling in the gas oilboiling range. The feed oil is introduced into solvent treating zone Iby means of feed line 2. It is also assumed that the solvent comprises astrong aqueous or alcoholic caustic solution which is introduced intosolvent treating zone 5 by means of line 3. Operating conditions areadapted to remove the naturally occurring high molecular weight phenolsfrom the feed oil which is withdrawn from solvent treating zone l bymeans of line 4 and handled in any manner desirable. The aqueoussolution of alkali metal phenolates is withdrawn from solvent treatingzone I by means of line 5 and preferably introduced into a secondarysolvent treating zone 6 in which it is contacted with a secondarysolvent, as for example a petroleum ether or naphtha, which has theability to dissolve the residual feed oil hydrocarbon constituents. Forpurposes of illus tration it is assumed that the secondary solventcomprises a low boiling petroleum oil which is introduced into solventtreating zone 6 by means of line I and is withdrawn along with theresidual hydrocarbon constituents by means of line B. The alkali metalalcoholic s lution of phenolates is then passed into regeneration zone iby means of line 9. in which the corresponding phenols are regeneratedfrom the phenclate salts bymeans of carbon dioxide, which is introducedinto zone The spent solution is withdrawn from zone I by means of lineH, while the crude phenol fraction is withdrawn by means of line 12 andpassed into distillation zone l3. Prior to introducing the crudefraction into distillation zone It, it is mixed with a relativelyhigh-boiling, high molecular weight petroleum fraction which for thepurposes of illustration is assumed to be a petroleum asphalt. Thisfraction is introduced into the crude phenol fraction by means of lineIt. Temperature and pressure conditions are adjusted in distillationzone [3 to remove overhead by means of line l5 high quality petroleumc-il phenols, and to remove as a bottoms by means of line It a fluidresidue.

The process of the present invention may be Widely varied. The operationessentially comprises distilling crude petroleum phenols in the presenceof an added high molecular weight, high-boiling petroleum residue underconditions in which the yield of overhead refined phenols is increasedand in which excessive polymerization and decomposition of valuablecrude phenols is prevented. The process may be adapted for the treatmentof crude phenols secured from any mineral oil by any conventionalprocedure. However, the operation is particularly adapted for refiningcrude phenols secured from petroleum oils, particularly relatively highmolecular weight crude phenols segregated from petroleum oils boiling inthe gas oil, heating oil and higher boiling ranges.

A particularly desirable method for segregating these naturallyoccurring phenols from phenols from phenol containing petroleum oils isto treat the petroleum oil with a suitable alkali, as for example sodiumor potassium hydroxide or the like, in order to form the alkali metalphenolates.

The neutralizing temperature employed is preferably atmospheric,although other temperatures may be utilized. The amount andconcentration of the alkali used in the neutralization stage will besufficient to secure substantially complete conversion of the phenols tothe corresponding alkali metal phenolates. In general it is preferred touse from 0.02 to 0.05 volume of alkali solution per volume of phenolcontaining feed oil. Under these conditions the concentration of thealkali should preferably be in the range from about to It is, however,to be understood that the concentration and amount of alkali employedwill depend upon the concentration of the phenols in the phenolcontaining oil. It is necessary in order to secure high yields ofpurified phenols that an excess amount of alkali be employed in order toprevent the hydrolysis of the alkali metal phenolates to thecorresponding phenols.

The solvent used to remove the residual constituents of the feed oilfrom the alkali metal phenolates may be any suitable solvent which willdissolve these oil constituents. In general, solvents of the class oflower boiling petroleum hydrocarbons are employed, specific examples ofwhich are solvent naphtha and petroleum oils boiling in the motor fuelboiling range. The quantity of solvent used in the primary alkali metalphenolate treating stage will depend upon the particular solvent beingused and the amount and character of the residual petroleum oilconstituents present. In general, it is preferred to use from aboutone-half to four volumes of solvent per volume of alkali metal phenolatesolution. The temperature and pressure conditions employed in thesolvent treating stage likewise depend upon the particular solvent usedand the character of the residual oil being separated from the alkalimetal phenolates. In

general, it is preferred to use atmospheric pressure and a temperaturein the range from about F. to F.

The alkali metal phenolate solution is acidified by treatment with anysuitable acid, as for example sulfuric acid, hydrochloric acid, and thelike. In general, it is preferred to regenerate the correspondingphenols from the phenolate salts by treatment with carbon dioxide and toseparate the liberated phenols from the spent aqueous solution.

Although the above described method of segregrating the crude phenolfraction from the phenol containing petroleum oil is generally employed,it is to be understood that crude phenols segregated by any suitablemeans may be likewise treated in accordance with the present process.For example, the present operation is particularly adapted for therefinement of relatively high molecular weight phenols and naphthenicacids segregated from feed oils containing the same by use of variousadsorbents such as various zeolites, bauxite, and the like.

The crude phenols, segregated in the manner described, are blended priorto distilling the same with a relatively high molecular weight petroleumhydrocarbon. In general, these materials should have a gravity in therange from about 10.0 to about A. P. I. and boil in the range aboveabout 220 C. at 10 mm. Hg (absolute). A particularly desirable additionagent comprises a heavy petroleum asphalt having a gravity of about 13.0to about l4.0 A. P. I.

The amount or" the addition agent added will depend upon the characterof the crude phenols and the particular high molecular Weight petroleumhydrocarbons added. In general the amount of heavy petroleum oil addedis in the range from about 5% to about 30%, preferably from about 15% to25%.

In order to further illustrate the present invention, the followingexamples are given which should not be construed as limiting the same inany manner whatsoever:

EXAMPLE 1 Various crude petroleum phenol fractions were distilled in anumber of operations. The results secured when employing a highmolecular weight petroleum oil as compared to operations in which thepetroleum oil was not employed are as follows:

Crude phenol fraction distilled Without added high boiling- Withadidtion of pet. asphalt having A. P. I. gravity of 13.4"

Pot. Oil

Carrier Final bottoms temp, O. Absolute pressure, mm. Hg Percentpetroleum asphalt adderL. Yield percent overhead N ature of bottomsSteam Hard 'tch 2. 23

Per cent unsaponifiaole in overhead 2. 04

phenols from crude phenol fractions segregated from mineral oilscomprising distilling a feed crude phenol fraction in the presence of anadded high molecular weight petroleum asphalt under conditions to removeoverhead the refined phenols and to remove as a fluid bottoms productthe added hydrocarbon and the impurities present in the feed phenolfraction.

2. Process in accordance with claim 1 in which said crude phenolfraction is segregated from a petroleum oil and in which the addedpetroleum asphalt comprises a petroleum asphalt having a gravity in therange from about 10.0 to about 150 A. P. I.

3. Process in accordance with claim 1 in which said feed phenol fractioncomprises high molecular weight naturally occurring phenols and in whichabout 5.0 to about 30.0% of a petroleum asphalt having a gravity in therange of about 10.0 to about 150 A. P. I. is added.

4. Process for the segregation and recovery of high quality phenols frompetroleum oils containing the same comprising treating a petroleum feedoil with a caustic solution under conditions to convert the phenols tocorresponding alkali metal phenolates, separating the alkali metalphenolates from the treated feed oil, reextracting the separated alkalimetal phenolates with a solvent having the ability to dissolve residualfeed oil constituents, separating the alkali metal phenolates,liberating the phenols and distilling the same in the presence of anadded high molecular weight petroleum asphalt having an A. P. I.

gravity in the range from about 10 to about 15, under conditions toremove overhead the refined phenols and to remove as a fluid bottomsproduct the added hydrocarbon and the impurities present in the feedphenol fraction. I

5. Process in accordance with claim 4 in which the added high molecularweight petroleum asphalt comprises a petroleum asphalt having a gravityin the range from about 13 to about 14 A. P. I.

6. Process for the segregation and recovery of high quality phenols frompetroleum oils containing the same comprising treating 'a petroleum feedoil with a zeolite under conditions to remove the phenols from the feedoil, removing the treated oil and treating the zeolite to recover thephenols therefrom, then distilling the crude phenol fraction in thepresence of an added high molecular weight petroleum asphalt having anA. P. I. gravity in the range from about 10 to 15, under conditions toremove overhead the refined phenols and. to remove as a fiuid bottomsproduct the added hydrocarbon and the impurities present in the feedphenol fraction.

7. Process in accordance with claim 6 in which said feed phenol fractioncomprises high molecular weight naturally occurring phenols and in whichthe added high molecular weight petroleum hydrocarbon comprises about5.0 to about 30.0% of a petroleum asphalt having a gravity in the rangeof about 10.0 to about 15.0 A. P. I.

ROBERT A. GERLICHER.

